Shower thank you gifts for junior hostesses?

A close friend is hosting my shower on Sunday. She has two daughters, ages 9 & 12, who are super excited and have been very helpful and involved. I would like to get them something special, but what I am giving their mom (wine, candle, etc) clearly won't be appropriate :) Any ideas?

Nail polish, body sprays, hair accesseries, lip gloss. You could make like a basket with things like that. Maybe a $5 giftcard to somewhere like a fast food place or frozen yogurt/ice cream place (somewhere their mom approves of).